You know, at least atheism has a pretty much unanimous philosophy.
Even within the Christian faith, there are several sects. I've seen friendships destroyed because one guy's faith didn't match the other guy's faith. It's petty and stupid; "No, MY interpretation of the bible is correct, yours is WRONG!". One sect takes it literally at face value, the other believes in metaphorical interpretations. Who is right? Neither.
Religion has been the cause of most of the wars of human history.
IF the whole world converted to atheism, at least wars won't be fought over petty metaphysical ideals. Politicians would not be able to sell us this "God told me to do it" crap that George W. Bush said right after he invaded Iraq. Don't try to tell me that religion didn't play a part in that war when I'm literally surrounded by retarded rednecks who spout shit like "let's kill us some Muslim devils!".
In short, religion is a strong factor for bigotry, racism, ignorance, illiteracy, propaganda, and wars. Adolf Hitler himself was a Catholic, go figure right? Personally, I think religion should have died a long time ago, when Darwin wrote his famous book "the origin of species". But no, it didn't go away, because people would rather believe in a 2000 year old book written in a time of virtually no science, than actually be open to innovative ideas like evolution.
"Blind faith" is dangerous. It supersedes logic, defies common sense, and the only way to sustain is to lie to oneself.
THIS is why I have a problem with religion. It causes unrepairable harm to society as a whole, and worse, destroys the individual. The only people who benefit from it are politicians, ministers, and the Pope.